Arc lamp



H. 'M. J. BENARD J ARC LAMP July 22, 1930.

Filed Aug. 15, 1928 J Invenlbr flnri LMJfienard I Uikwm/ rm Patented July 22, 1930 UNITED STATES HENRI LUGLIENFMARIE .iosnrn BENARD, or rams, FRANCE, assrcnon 'ro momma PATENT oFmcE ETABLISSEMENTS BABBIEB, BENARD ET TURENNE, SOCIETE ANONYME, F PARIS, FRANCE, A. JOINT-STOCK COMPANY OF FRANCE 7 ARC LAMP Application flled August 15, 1928, Serial No. 259,794, and in France October 6, 1927.

The present invention relates to improvements in arc lamps and it is more particularly concerned with the type of arc lamps in which the position of one of the carbons is controlled by a continuous forward feed mechanism which is regulated according to the rate of consumption of said carbon,

whilst the position of the other carbon is controlled by an automatic adjusting mecha- 10 nism intermittently actuated b any suitable means responsive to the electrical quantities of the arc, for advancing said carbon and maintaining the length of the are constant.

The present invention relates more par-,

ticularly to, an automatic adjusting mechanism of the type indicated above and which is preferably applied to the more rapidly and more irregularly consumed carbon of the.

two, that is to say, to the positive carbon.

The mechanism according to the invention is essentially characterized by the fact that it comprises a hollow continuously rotating shaft through which the carbon extends, a wheel carrying pawls which serves to advance said carbon,being mounted on saidshaft to rotate therewith, whilst capable of being displaced axially thereof by means responsive to the electrical quantities of. the arc, said pawls being so disposed as to allow of rotational movement of the carbon and intermittent translational movementthereof in one.

direction only.

According to a form of embodiment of the invention, the above specified means are constituted by a toothed wheel with which a locking device cooperates, said toothed wheel being threaded on to the hollow shaft and acted on by a torsionally operating spring which always tends to screw th'e'wheel on j the shaft and is secured to the wheel and aft and is constrained byan annular mem-.

her to follow the toothed wheel in its translational movement, said pawl-carrying wheel being continuously rotated by the hollow shaft through the medium of a pin screwed into said wheel and projecting into a groove made in the hollow shaft.

The invention has been illustrated diagrammatically and merely by way of example in the following drawing in which:

Fig. l is a longitudinal elevation, partly in section, of the automatic advancing mechanism in accordance with the invention.

Fig. 2 is a diagrammatic end elevation of the mechanism illustrated in Fig. 1.

. The automatic advancing mechanism for the positive carbon of the arc lamp is essentially constituted by a hollow shaft 1 to which a continuous movement of rotation is imparted by a gear train 2, 3, whilst the carbon 4 whose position is to be regulated passes through said shaft.

A toothed wheel 5 is mounted on the hollow shaft 1 and has an extension piece 5 screwed on said shaft. A torsion spring 6, one end of which is fixed to the toothed wheel 5 whilst the other end is fixed to a collar 7 integral with the hollow shaft 1, acts on the toothed wheel 5. The tendency of the spring 6 is to screw the toothed wheel 5 towards the right on the hollow shaft 1 and it is through its instrumentality that the shaft 1 rotates the wheel 5. I a

In addition, a pawl-carrying wheel 8 is slidably mounted on the shaft 1. An extension 9 of the wheel 8 has a shoulder 9 engaging in a recess 5 of the wheel 5 to which latter thereis screwed, or otherwise secured, a ring9". The pawls 10 of the wheel 8 project through grooves made in the hollow shaft through the medium ofa pin 10 screwed into the wheel 8 and projecting into a groove 11 made in the shaft 1.

The periphery of the wheel 5 is provided with toothing 12 with which there cooperates a sliding finger 13 mounted in the frame 14 of the apparatus, said finger 13 being responsive to the electrical quantities of the arc and it may engage with the toothing 12 to prevent the wheel 5 from being rotated by the shaft 1.

The mode of operation of the mechanism is as follows:

Under normal circumstances, that is to say, when the values of the electrical quantities of the are under consideration are normal, the hollow shaft 1 rotates the toothed wheel 5 and the pawl 'arryiug wheel 8 which latter in its turn rotates the carbon 4. As soon as a disturbance occurs in the electrical quantities of the arc, and, particularly, when the arc is too great, said electrical quantities act on the finger 13 through any suitable means, for example through the medium of electrical relays, which have not been illustrated, to bring said finger into engagement with the toothing 12 of the wheel 5. The consequence is that the toothed wheel 5 can no longer be rotated by the shaft 1 and hence said toothed wheel 5 unscrews towards the left over the shaft 1. The wheel 5 is therefore shifted longitudinally of the shaft 1 in the direction of the arrow 15 and displaces the pawl-carrying wheel 8 through the medium of the shoulder 9 on the extension 9 of said wheel. The result is that the carbon t whilst continuously rotating, travels through the hollow shaft 1 in the direction of the arrow 15 towards the negative carbon of the arc lamp. The effect of thus bringing the carbons nearer together is to reestablish the normal conditions of the electrical quantities of the are, and the relays or other means responsive to said quantities cease to act on the finger 13 so that the latter moves out of engagement with the toothing 12 of the wheel 5. As soon as the finger 13 is released from the toothing 12, the torsion spring 6 becomes operative and retracts the toothed wheel 5 to the right back to the position it occupies under normal conditions. The toothed wheel 5 again acts on the pawl-carrying wheel 8, but in the opposite direction to the preceding one, through the medium of the ring 9 engaging the shoulder 9 of the extension 9, and said pawl-carrying wheel 8 also comes back to the rear in the direction of the arrow 16. Naturally, during the backward movement of the pawl-carrying wheel 8, the pawls 1O momentarily release the carbon 4 over which they slide, on account of their inclined position which is about to be defined.

t will be gathered from the preceding description that the mechanism according to the invention enables two movements to be imparted to the positive carbon of the arc lamp, firstly, a continuous rotational move ment and, secondly, an intermittent translational movement which enables the values of the electrical quantities of the arc to be maintained normal. To render these two movements possible, the pawls 10 of the pawl carrying wheel 8 should be so disposed that their pivot axis 17 is parallel, or substantially parallel, to the tangent to the helix described by the point of contact of the pawls 10 and the carbon 4 when a rotational and a translational movement are imparted atone and the same time to the pawl-carrying wheel 8.

It is moreover self-evident that the invention has only been described and illustrated here in a purely explanatory but by no means limitative manner, and that it could be subjected to various modifications of detail without departing from the spirit thereof.

I claim:

1. A device for regulating the distance between the carbons of an arc lamp, comprising, in combination, a hollow shaft, means for continuously rotating said hollow shaft, a carbon displaceable within said hollow shaft, a wheel mounted on said shaft to rotate therewith whilst capable of translational movement along said shaft, pawls carried by said wheel and projecting through slots in said shaft to engage with said carbon whereby said carbon is continuously rotated, said pawls being so inclined to said carbon as to shift the same in one direction of translational movement of said wheel, and means responsive to change in the normal values of the electrical quantities of the are for shifting said wheel along said shaft whereby said carbon is brought towards a fixed carbon.

2. A device for regulating the distance between the carbons of an arc lamp, comprising, in combination, a hollow shaft, means for continuously rotating said hollow shaft, :1 carbon displaceable within said hollow shaft, a wheel mounted on said shaft to rotate therewith whilst capable of translational movement along said shaft, pawls carried by said wheel and projecting through slots in said shaft to engage with said carbon where by said carbon is continuously rotated, said pawls being so inclined to said carbon as to shift the same in one direction of translational movement of said wheel, means responsive to change in the normal values of the electrical quantities of the are for shifting said wheel along said shaft whereby said carbon is brought towards a fixed carbon, and means tending to retain said wheel shiftlng means.

3. A device for regulating the distance between the carbons of an arc lamp, comprising, in combination, a hollow shaft, means for continuously rotating said hollow shaft, a carbon displaceable within said hollow shaft, a wheel mounted on said shaft to rotate therewith whilst capable of translational movement alon said shaft, pawls carried by said wheel an projecting throu h slots in said shaft to engage with said car on whereby said carbon is continuously rotated, said pawls being so inclined to said carbon as to shift the same in one direction of translational movement of said wheel, a toothed wheel screw-threaded on said shaft and displaceable axially thereof, a member connecting said toothed wheel and pawl-carrying wheel together, and a finger responsive to change in the normal values of theelectrical quantities of the are for engaging in the teeth of said toothed wheel whereby said toothed wheel is prevented from rotating and hence unscrews along said shaft shifting said carbon through the medium of said pawl-carrying wheel.

4. A device for regulating the distance between the carbons of an arc lamp, comprising, in combination, a hollow shaft,means for continuously rotating said hollow shaft, o a carbon displaceable within said hollow shaft, a wheel mounted on said shaft to rotate therewith whilst capable of translational movement along said shaft, pawls carried by said wheel and projecting throu h slots in said shaft to engage with said car on whereby said carbon is continuously rotated, said pawls being so inclined to said carbon as to shift the same in one direction of translational movement of said wheel, a toothed wheel screw-threaded on said shaft and displaceable axially thereof, a member connecting said toothed wheel and pawl-carrying wheel together, a sprin fixed at its ends to said toothed wheel an shaft respectively,

and a finger responsive to change in the normal values of the electrical quantities of the arc for engaging in the teeth of said toothed wheel whereby said toothed wheel is prevented from rotating and hence unscrews along said shaft tensioning said spring and displacing said carbon through the medium of said pawl-carrying wheel.

HENRI LUGLIEN MARIE JOSEPH IENARD. 

